Java tutorial
package com.thinkbiganalytics.servicemonitor.rest.client.cdh; /*- * #%L * thinkbig-service-monitor-cloudera * %% * Copyright (C) 2017 ThinkBig Analytics * %% * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * #L% */ import com.cloudera.api.ApiRootResource; import com.cloudera.api.v1.RootResourceV1; import org.apache.commons.lang3.StringUtils; import org.apache.commons.lang3.reflect.MethodUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Cloudera resource manager which first attempts to get configured Cloudera API version and if that fails it * falls back to first API version. */ class ClouderaRootResourceManager { private static final Logger LOG = LoggerFactory.getLogger(ClouderaRootResourceManager.class); /** * Will attempt to get configured api version. If that fails it will fall back to API v1. */ static ClouderaRootResource getRootResource(ApiRootResource apiRootResource) { String version = apiRootResource.getCurrentVersion(); Integer numericVersion = new Integer(StringUtils.substringAfter(version, "v")); RootResourceV1 rootResource = null; Integer maxVersion = 10; if (numericVersion > maxVersion) { numericVersion = maxVersion; } try { rootResource = (RootResourceV1) MethodUtils.invokeMethod(apiRootResource, "getRootV" + numericVersion); } catch (Exception ignored) { } if (rootResource == null) { LOG.info("Unable to get RootResource for version {}, returning version 1", numericVersion); rootResource = apiRootResource.getRootV1(); } return new DefaultClouderaRootResource(rootResource); } }